Microwave Heating Glass Bending Process

ABSTRACT

Methods and systems are provided for automated shaping of a glass sheet. The methods comprise preheating the glass, bending the glass through selective, and focused beam heating through the use of an ultra-high frequency, high-power electromagnetic wave, and computer implemented processes utilizing thermal and shape (positional) data obtained in real-time, and cooling the glass sheet to produce a glass sheet suitable for use in air and space vehicles.

BACKGROUND OF THE INVENTION Field of the Invention

This invention relates to a heating and bending (and/or shaping) systemusing microwave focused beam heating, and more particularly, to a glassline having at least two, for example, at least three, heating furnaces.Wherein the first heating furnace is used to preheat one or more glasssubstrates to a first temperature; the second heating furnace, being aglass forming furnace, maintains the substrates at the first temperatureand heats and bends selected portions of the one or more glasssubstrates using microwave focused beam heating, and the first heatingfurnace, or a third furnace, controllably cools the one or more glasssubstrates.

Also provided herein are methods for real-time monitoring of thetemperature and bending of a glass sheet to be shaped.

Description of the Related Art

Bending devices, commonly referred to in the bending art as bendingirons or shaping irons, are well known in the art for shaping one ormore glass sheets for use in the manufacture of monolithic and laminatedtransparencies for land, water, air and space vehicles. The method forshaping the glass substrates or sheets for use in the manufacture oftransparencies for land and water vehicles usually includes providingone or more glass sheets having seamed or smoothed edges and apredetermined size; moving the glass sheets supported on a bending ironthrough a furnace to heat soften the glass sheets; shaping the glasssheets; controllably cooling the shaped glass sheets to anneal orthermally temper the shaped glass sheets, and using the shaped glasssheets in the manufacture of a transparency for a land or water vehicle.The method for shaping glass substrates or sheets for use in themanufacture of transparencies for air and space vehicles usuallyincludes providing one or more glass sheets having seamed or smoothededges and a predetermined size; moving the glass sheets supported on abending iron through a furnace to heat soften the glass sheets; shapingthe glass sheets; controllably cooling the shaped glass sheets to annealthe shaped glass sheets; cutting the shaped glass sheets to a secondpredetermined size; seaming or smoothing the edges of the shaped glasssheets; chemically tempering the shaped glass sheets, or thermallytempering the shaped glass sheets, and using the tempered shaped glasssheets in the manufacture of a transparency for an air or space vehicle.

The difference of interest in the present discussion between shapingglass sheets for use with transparencies for land and water vehicles andshaping glass sheets for use with transparencies for air and spacevehicles is that the glass sheets for use with transparencies for landand water vehicles are cut to size before shaping or bending, whereasglass sheets for use with transparencies for air and space vehicles arecut to an over size before shaping and then cut to size after bending.For purposes of clarity, the process presently available for shapingglass sheets for use with transparencies for land and water vehicles isalso referred to as “cut-to-size process”, and the process presentlyavailable for shaping a glass sheet for use with transparencies in airand space vehicles is referred to as “cut-after-bend process”.

The cut-to-size process allows cutting of the glass sheet to the exactsize desired prior to the heating and bending of the glass sheet.However, the cut-to-size process does not account for any possiblemarring that may occur on the surface of the glass sheet, which can makethe optical quality of the glass sheet and subsequently formedtransparency unacceptable.

One solution to this problem is to provide a bending iron that hasimprovements in its design to prevent the marring of the surface of theglass sheet in contact with the bending iron. Such a bending iron isdisclosed in U.S. patent Ser. No. 13/714,494. Another solution to thisproblem is to reduce the temperature of the furnace and/or the timeperiod of the heating cycle for shaping the glass sheets to reduce oreliminate marring of the surface of the glass sheet in contact with thebending iron during the sheet shaping process.

As can now be appreciated by those skilled in the art, it would beadvantageous to provide a process of, and/or equipment for, shapingglass sheets for use in aircraft and space transparencies using thecut-to-size process, while eliminating or reducing marring of thesurface of the glass sheet in contact with the bending iron.

It would also be advantageous, to eliminate the process of“cut-after-bend” by providing a system and method that allow for theefficient and effective heating, and/or shaping into complex shapes,and/or cooling of a sheet of glass.

SUMMARY OF THE INVENTION

Provided herein are methods and systems for producing complex glasssheet shapes in an efficient, and automated manner. The methods andsystems provided herein are an improvement over previous technologies inthat they allow for precise, tailor-made shapes, without the use ofexcessive heat and the resulting increase in the likelihood of marring.Further, by real-time feedback, the methods and systems described hereinensure that the complex shapes are achieved every time.

Provided herein are methods and systems for shaping, and/or, bending aglass sheet comprising: preheating a glass sheet on a bending iron to apreheating temperature ranging from 600° F. to 1000° F.; increasing thetemperature of the sheet to a temperature ranging from greater than thepreheating temperature to less than a temperature at which the glasssags, for example in a temperature range of, but not limited to, 1100°F. to 1250° F. Bending the glass sheet by: i.) selectively heating aportion of the glass sheet with a gyrotron beam controlled by acomputer-implemented protocol to a temperature at which at least aportion of the glass sheet sags; ii.) scanning at least a portion of theglass sheet with one or more infrared (IR) scanners at one or more timepoints during or after the selective heating step and obtaining fromdata obtained from the one or more IR scanners a temperaturedistribution in at least two dimensions for at least a portion of theglass sheet; iii.) comparing, using a computer-implemented process, theobtained temperature distribution to a reference temperaturedistribution of the computer-implemented protocol; and selectivelyheating the glass sheet with the gyrotron beam controlled by acomputer-implemented process to match the obtained temperaturedistribution with the reference temperature distribution of thecomputer-implemented protocol.

Additionally provided herein is a system comprising: a first furnace,also herein referred to as the glass preheating chamber/oven, comprisinginfrared heaters and temperature sensors; a second furnace, also hereinreferred to as the glass shaping, glass bending, and/or glass formingfurnace, comprising infrared heaters, a gyrotron system comprising agyrotron device, or other device that can produce ultra-high frequency,e.g., at least 20 GHz (gigahertz), for example ranging from 20 GHz to300 GHz, and high-power, e.g., at least 5 kW (kilowatt) electromagneticwaves within the microwave spectrum, and an optical system forcontrolling shape, location and movement of a beam of the gyrotrondevice to a glass sheet on a bending iron within the second furnace, andone or more infrared (IR) imaging sensors; a conveyor system forcarrying a glass sheet on a bending iron through the first and secondfurnaces; a computer system connected to the one or more IR imagingsensors and the gyrotron system, comprising a processor and instructionsfor controlling bending of a glass sheet in the second furnace byselective heating by the gyrotron system, the instructions comprising acomputer-implemented protocol for heating and bending a glass sheet inthe second furnace, where the computer system obtains a temperatureprofile of the glass sheet at one or more time points during the bendingof the glass data from the one or more IR imaging sensors, compares theobtained temperature profile to a reference temperature distribution ofthe computer-implemented protocol, and controls the gyrotron beam systemto selectively heat the glass sheet to match the reference temperaturedistribution. The system optionally contains a third heating furnace tocontrollably cool the glass sheet. The third furnace comprising IRheaters, a forced cool air convection system, and air fans. If a thirdfurnace is not present, then the first furnace will contain all of thesefeatures.

In addition, this invention relates to a method of operating a furnacesystem to shape a glass sheet for, e.g., an aircraft transparency, themethod includes, among other things:

-   a) placing a flat glass sheet on a bending iron having a fixed    shaping rail and a shaping rail on an articulating arm defined as a    moveable shaping rail;-   b) positioning the bending iron having the glass sheet in an    interior of a furnace to heat the glass sheet to shape the glass    sheet on the fixed shaping rail while moving a beam of microwave    energy from a gyrotron to heat portions of the glass sheet    overlaying the moveable shaping rail to shape the portions of the    glass sheet by movement of the articulating arm;-   c) obtaining and transmitting to a computer one or more thermal    images of at least a portion of the glass sheet from one or more IR    imaging sensors, and optionally one or more shape profile images    from one or more 3D imaging sensors;-   d) analyzing using a computer-implemented method the one or more    thermal images and optionally the one or more shape profile images,    and comparing the images with a computer-implemented method to one    or more reference thermal images, and optionally one or more    reference shape profile images, to determine a difference between    the one or more thermal and, optionally, shape profile images and    the reference images;-   e) based on a predetermined heat (power and speed) profile as    reference, directing, using a computer-implemented method, a beam of    microwave energy from the gyrotron, or other suitable source, to    heat portions of the glass sheet to match the one or more reference    thermal images, and optionally to match the one or more reference    shape profile images, repeating the analyzing and comparing steps    until the one or more thermal images match the one or more reference    thermal images, and optionally until the one or more shape profile    images matches the one or more reference shape profile images;-   f) through the computer-implemented methods, producing a glass    viscosity distribution, allowing the glass sheet to be formed or    bent into a required shape with acceptable optical quality; and-   g) controllably cooling the shaped glass sheet.

BRIEF SUMMARY OF THE DRAWINGS

FIG. 1 is a cross sectional view of a laminated aircraft transparencyillustrating the laminated structure of the transparency.

FIG. 2 is a perspective view of shaped sheets that are shaped inaccordance to the teachings of the invention.

FIG. 3 is a perspective view of flat sheets that can be shaped inaccordance to the teachings of the invention to, among other things,provide the shaped sheets of FIG. 2 .

FIG. 4 is perspective view of a non-limiting embodiment of a bendingdevice that can be used in the practice of the invention to, among otherthings, shape glass sheets, e.g., but not limited to, the sheets of FIG.3 , to the shaped sheets shown in FIG. 2 .

FIG. 5 is perspective view of a non-limiting embodiment of a furnacesystem that can be used in the practice of the invention to, among otherthings, heat and shape glass sheets, e.g., but not limited to, heatingand shaping the sheets of FIG. 3 to the shaped sheets shown in FIG. 2 inaccordance to the teachings of the invention.

FIG. 6 is an elevated cross sectional view of the furnace shown in FIG.5 .

FIG. 7 is a perspective view of a furnace door having portions removedfor purposes of clarity incorporating features of the invention toreduce heat loss between adjacent interiors of the furnace system shownin FIGS. 5 and 6 .

FIG. 8 is a perspective view of a carriage for supporting the bendingiron, e.g., but not limited to, the bending iron shown in FIG. 4 and amoveable conveyor section to move the carriage into the entrance end ofthe furnace shown in FIGS. 5 and 6 .

FIG. 9 illustrates a microprocessor for receiving signals from sensorsand acting on the signals in accordance to the teachings of theinvention.

FIG. 10 is a schematic partially in cross section showing a gyrotronthat can be used in the practice of invention to heat selected portionsof a glass sheet.

FIG. 11 is a plan view showing the path of the microwave beam of thegyrotron to selectively heat portions of a stack of one or more glasssheets.

FIG. 12 is an elevated cross sectional side view of a furnace systemincorporating features of the invention that can be used in the practiceof the invention to, among other things, heat and shape glass sheets.

FIG. 13 is an elevated plan view of a furnace system incorporatingfeatures of the invention that can be used in the practice of theinvention to, among other things, heat and shape glass sheets.

FIG. 14 is an elevated cross sectional view of a furnace of theinvention that can be used in the practice of the invention to, amongother things, heat and shape glass sheets.

FIG. 15 is an elevated cross sectional view of a furnace system of theinvention.

FIG. 16 illustrates a flow diagram of a method of shaping a glass sheetin accordance with the invention.

DETAILED DESCRIPTION

As used herein, spatial or directional terms, such as “left”, “right”,“inner”, “outer”, “above”, “below”, and the like, relate to theinvention as it is shown in the drawing figures. However, it is to beunderstood that the invention can assume various alternativeorientations and, accordingly, such terms are not to be considered aslimiting. Further, as used herein, all numbers expressing dimensions,physical characteristics, processing parameters, quantities ofingredients, reaction conditions, and the like, used in thespecification and claims are to be understood as being modified in allinstances by the term “about”. Accordingly, unless indicated to thecontrary, the numerical values set forth in the following specificationand claims can vary depending upon the desired properties sought to beobtained by the present invention. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical value should at least be construedin light of the number of reported significant digits and by applyingordinary rounding techniques. Moreover, all ranges disclosed herein areto be understood to encompass the beginning and ending range values andany and all subranges subsumed therein. For ranges between (andinclusive of) the minimum value of 1 and the maximum value of 10; thatis, all subranges beginning with a minimum value of 1 or more and endingwith a maximum value of 10 or less, e.g., 1 to 3.3, 4.7 to 7.5, 5.5 to10, and the like. Further, as used herein, the term, “over” means on butnot necessarily in contact with the surface. For example, a firstsubstrate “over” a second substrate does not preclude the presence ofone or more other substrates of the same or different compositionlocated between the first and the second substrates.

Before discussing the invention, it is understood that the invention isnot limited in its application to the specific illustrated examples asthese are merely illustrative of the general inventive concept. Further,the terminology used herein to discuss the invention is for the purposeof description and is not of limitation. Still further, unless indicatedotherwise in the following discussion, like numbers refer to likeelements.

For purposes of the following discussion, the invention will bediscussed with reference to shaping a sheet for an aircrafttransparency. With regard to the instant application, the term “glassshaping” refers to the concept of glass bending and/or glass forming.These terms are used interchangeably throughout the instant application.As will be appreciated, the invention is not limited to the material ofthe sheet, e.g., the sheet can be, but is not limited to, a glass sheetor a plastic sheet. In the broad practice of the invention, the sheetcan be made of any desired material having any desired characteristics.For example, the sheet can be opaque, transparent or translucent tovisible light. By “opaque” is meant having visible light transmission of0%. By “transparent” is meant having visible light transmission in therange of greater than 0% to 100%. By “translucent” is meant allowingelectromagnetic energy (e.g., visible light) to pass through butdiffusing this energy such that objects on the side opposite the viewerare not clearly visible. In the preferred practice of the invention, thesheet is a transparent glass sheet. The glass sheet can includeconventional soda-lime-silica glass, borosilicate glass, orlithia-alumina-silica glass. The glass can be clear glass. By “clearglass” is meant non-tinted or non-colored glass. Alternatively, theglass can be tinted or otherwise colored glass. The glass can beannealed, heat-treated or chemically tempered. In the practice of theinvention, the glass can be conventional float glass, and can be of anycomposition having any optical properties, e.g., any value of visibletransmission, ultraviolet transmission, infrared transmission, and/ortotal solar energy transmission. By “float glass” is meant glass formedby a conventional float process. Examples of float glass processes aredisclosed in U.S. Pat. Nos. 4,744,809 and 6,094,942, which patents arehereby incorporated by reference.

In one example of the invention, the glass was a clearlithia-alumina-silica glass of the type disclosed in U.S. Pat. No.8,062,749, and in another example of the invention the glass was a clearsoda-lime-silica glass of the type disclosed in U.S. Pat. Nos.4,192,689; 5,565,388; and 7,585,801.

The glass sheet can be used in the manufacture of shaped monolithic orshaped laminated transparencies for an aircraft. However as can beappreciated, the shaped glass sheets of the invention can be used in themanufacture of any type of transparency, such as but not limited towindshields, windows, rear lights, sunroofs and moon roofs; laminated ornon-laminated residential and/or commercial windows; insulating glassunits, and/or transparencies for land, air, space, above water and underwater vehicles. Non-limiting examples of vehicle transparencies,residential and commercial transparencies, and aircraft transparenciesand methods of making the same are found in U.S. Pat. Nos. 4,820,902;5,028,759; 6,301,858; and 8,155,816, which patents are herebyincorporated herein by reference.

Shown in FIG. 1 is a cross-sectional view of an exemplary laminatedaircraft windshield 20 that has components that can be made by thepractice of the invention. The windshield 20 includes a first glasssheet 22 secured to a vinyl-interlayer or sheet 28 by a first urethaneinterlayer 30, and the vinyl-interlayer 28 is secured to a heatablemember 32 by a second urethane interlayer 34. An edge member or moisturebarrier 36 of the type used in the art, e.g., but not limited to, asilicone rubber or other flexible durable moisture resistant material,is secured to (1) a peripheral edge 38 of the windshield 20, i.e., theperipheral edge 38 of the vinyl-interlayer 28; of the first and secondurethane interlayers 30, 34 and of the heatable member 32; (2) marginsor marginal edges 40 of an outer surface 42 of the windshield 20, i.e.,the margins 40 of the outer surface 42 of the first glass sheet 22 ofthe windshield 20, and (3) margins or marginal edges 44 of an outersurface 46 of the windshield 20, i.e. margins of the outer surface 46 ofthe heatable member 32.

The first glass sheet 22, the vinyl-interlayer 28, and the firsturethane interlayer 30 form the structural part, or inner segment, ofthe windshield 20. The outer surface 42 of the windshield 20 faces theinterior of the vehicle, e.g., an aircraft (not shown). The urethanelayer 34 and the heatable member 32 form the non-structural part, orouter segment, of the windshield 20. The surface 46 of the windshield 20faces the exterior of the aircraft. The heatable member 32 provides heatto remove fog from, and/or to melt ice on, the outer surface 46 of thewindshield 20.

Shown in FIG. 2 , are two pieces of shaped glass sheets 60 and 61 shapedin accordance to the teachings of the invention. Each of the glasssheets 60 and 61 have curved end portions 62 and 64, and a shapedintermediate portion 66. For example, the shaped glass sheets 60 and 61can be shaped from flat glass sheets 68 and 69 shown in FIG. 3 using thebending iron 70 shown in FIG. 4 . The bending irons disclosed in U.S.patent application Ser. No. 13/714,494, entitled Bending Device ForShaping Glass For Use In Aircraft Transparencies filed on Dec. 14, 2012can be used in the practice of the invention. The disclosure of U.S.patent application Ser. No. 13/714,494 (hereinafter also referred to as“USPA '494”) in its entirety is incorporated herein by reference. For adetailed discussion of the bending iron 70, attention is directed toUSPA '494. FIG. 4 of this document corresponds to FIG. 4 of USPA '494.As can be appreciated, the invention is not limited to the bending iron70 and any design of a bending iron can be used in the practice of theinvention to shape one sheet or simultaneously shape two sheets 68 and69 (see FIG. 3 ), or shape more than two sheets to any desired shape.

FIGS. 5 and 6 show an exemplary furnace 74, e.g., but not limited to, afurnace system, or apparatus of the invention for heating and shapingglass sheets, e.g., but not limited to, the shaped glass sheets 68 and69. The furnace 74 includes a first chamber 76 or furnace and a secondchamber 78 or furnace. The first chamber 76 preheats a glass sheet,e.g., but not limited to the flat glass sheet 68 or flat glass sheets 68and 69 (see FIG. 3 ), supported or positioned on the bending iron 70(FIG. 4 ), and controllably cools the shaped glass sheet, e.g., but notlimited to the shaped glass sheet 60 or shaped glass sheets 60 and 61(FIG. 2 ), supported or positioned on the bending iron 70 to anneal theshaped glass sheets. The second chamber 78 selectively heats portions ofthe flat glass sheets 68 and 69 in accordance to the teachings of theinvention to shape the glass sheets 68 and 69 to a desired shape, e.g.,but not limiting to the invention, to the shape of the shaped glasssheets 60 and 61 shown in FIG. 2 .

The first chamber 76 has a first opening 80 (also referred to as the“entrance 80” of the first chamber 76) and a second opening 82 (alsoreferred to as the “exit 82” of the first chamber 76) opposite to andspaced from the first opening 80 (second opening clearly shown in FIG. 6). The second chamber 78 has a first opening 84 (also referred to as the“entrance 84” of the second chamber 78) and a second opening 86 (alsoreferred to as the “exit 86” of the second chamber 78) opposite to andspaced from the first opening 84 of the second chamber 78. With thisarrangement, the flat sheets 68 and 69 supported on the bending iron 70are moved through the first opening 80 of the first chamber 76 into aninterior 88 (see FIG. 6 ) of the first chamber 76 to preheat the glasssheets 68 and 69. The preheated glass sheets 68 and 69 are moved throughthe second opening 82 of the first chamber 76 and through the firstopening 84 of the second chamber 78 into an interior 90 (see FIG. 6 ) ofthe second chamber 78 to controllably heat the glass sheets 68 and 69 toshape the glass sheets in accordance to the teachings of the invention.The heated shaped glass sheets 60 and 61 are moved from the interior 90of the second chamber 78 through the first opening 84 of the secondchamber 78 and the second opening 82 of the first chamber 76 into theinterior 88 of the first chamber 76 to controllably cool the shapedglass sheets. Thereafter, the shaped glass sheets 60 and 61 are movedfrom the interior 88 of the first chamber 76 through the first opening80 of the first chamber 76.

The interior 88 of the first chamber 76 and the interior 90 of thesecond chamber 78 are separated from one another and from theenvironment exterior of the furnace 74 by providing a door 92 at theentrance 80 of the first chamber 76, a door 94 at the entrance 84 of thesecond chamber 78, and a door 96 at the exit 86 of the second chamber78. As can be appreciated, the invention is not limited to the type ofdoors 92, 94, 96 provided at the entrance 80, entrance 84, and exit 86,respectively, and any door design and/or construction can be used in thepractice of the invention. For example, the doors 92 and 96 can besimilar in design and construction. In view of the forgoing, thediscussion is now directed to the design and construction of the door 92with the understanding that the discussion, unless indicated otherwise,is directed to the door 96. With reference to FIG. 5 , the door 92 hassides 98 and 100 mounted in tracks 102 and 104 for reciprocal verticalmovement to move upwardly to open the entrance 80, and to movedownwardly to close the entrance 80, of the chamber 76, and for the door96 to move upwardly to open the opening 86, and to move downwardly toclose the opening 86. The opening 86 of the furnace 78 is used for,among other things, making repairs to, and performing maintenance on,the furnace 78; cleaning out the interior 90 of the furnace 78, e.g.,but not limited to removing broken glass, and for expansion of thefurnace 74 discussed in detail below.

The doors 92 and 96 are moved along the reciprocating vertical pathdesignated by double headed arrow 106 by a pulley arrangement 108including a pair wheels 110 and 112 spaced from one another and mountedon a rotating shaft 114. Cables 116, 118 have one end 120 secured to topside 121 adjacent to the sides 98, 100 of the doors 92 and 96,respectively (clearly shown for door 92) and opposite ends 124 of thecables 116, 118 each connected to an air cylinder 126 (clearly shown fordoors 92 and 96 in FIG. 5 ).

For example, the doors 92 and 94 can be each made of an outer metalhousing 127 having one side 128 made of steel, and the opposite side 129facing the interior of its respective one of the furnaces made ofstainless steel. The interior of the housing 127 can be filled withKaowool insulation 130 (clearly shown in FIG. 6 ).

The shaped glass sheets 60 and 61 are moved into the first furnace andannealed. The method of annealing glass sheets is well known in the art,e.g., see U.S. Pat. No. 7,240,519, which patent in its entirety ishereby incorporated by reference, and no further discussion is deemednecessary. After the sheets are annealed, the door 92 is lifted and theshaped glass sheets are removed from the first furnace 76. Thetemperature differential between the first furnace 76 and the secondfurnace 78 when the shaped glass sheets 60 and 61 are removed from thefirst furnace 76 can reach temperatures in the range of 800-1000° F.More particularly, the temperature of the first furnace 76 can be as lowas 200° F., the temperature the annealed shaped glass sheets 60 and 61are removed on the moveable conveyor 202 from the first furnace 76,whereas the temperature of the second furnace 78 can be greater than1000° F., the glass preheat temperature. To reduce heat loss between thefirst and the second furnaces 76 and 78, respectively, the door 94 canhave a thermal conductivity of less than 0.80 BTU/(hr·ft·° F.).

With reference to FIG. 7 , the exemplary door 94 includes a pipe frame94 a having a stainless steel 11 gage sheet 94 b secured to side 94 c ofthe pipe frame 94 a and a stainless steel 11 gage sheet 94 d secured toside 94 e of the pipe frame 94 a. A layer 133 of insulating materialsold under the registered trademark Super Firetemp® M having a thicknessof 1 1/2 inches was provided within the pipe frame 94 a between thestainless steel sheets 94 b and 94 d. A layer 94 g of insulatingmaterial is provided over the steel sheet 94 d and covered with0.008-0.010 inch thick stainless steel foil 94 h. The door 94 is mountedwith the stainless steel sheet 94 h facing the interior of the furnace78. Opening 94i and 94j are connected to a compressor (not shown) tomove room temperature compressed air through the pipe from 94 a to coolthe door 94 to prevent warping of the pipe frame 94 a and sheets 94 band 94 d. Optionally, the peripheral edge of the layers 94 g is coveredby the foil 94 h.

The door 94 is connected to a vertically reciprocating inverted U shapedmember 136 (clearly shown in FIG. 5 ). More particularly, the door 94 isconnected to a middle leg 137 of the U-shaped member 136 by rods 138,and outer legs 139 and 140 are mounted for reciprocal vertical movementin vertical tracks 141 and 142, respectively (see FIG. 5 ) in anyconvenient manner. The U-shaped member is moved vertically upwardly anddownwardly by an electric motor 145 (shown only in FIG. 6 ). With thedoor 94 in the down position, the entrance 84 of the furnace 78 isclosed, and with the door 94 in the up position, the entrance 84 of thefurnace 78 is open. In the up position, as shown in FIG. 6 , the door 94is moved into an envelope 146 formed on one side by a vertical extension148 of a metal roof 150 of the furnace 78 (see FIG. 6 ) and another side152 of the envelope 146 is made of a ceramic or metal wall securedbetween the tracks 140 and 142 (see FIG. 5 ).

The design and construction of the first furnace 76 is not limiting tothe invention and any type of furnace for heating or preheating a glasssheet to a desired temperature, e.g., a temperature below the softening,or sagging, temperature of the flat glass sheets 68 and 69 to avoidmarring of the surface of the glass sheets and for controllably coolingthe shaped glass sheet, e.g., but not limited to the shaped glass sheets60 and 61 in the manner discussed below. More particularly, a preheattemperature in the range of 600-900° F. is provided for alithium-soda-lime glass sheet, and a preheat temperature in the range of900-1025° F. is provided for a soda-lime-silica glass sheet. The firstfurnace 76 can include a side wall 160 (see FIG. 6 ) and an oppositesidewall 162 (see FIG. 5 ), a top wall or ceiling 164, and a bottom wall166 to provide the interior 88 of the furnace 76. Stub rolls 168extended through the sidewalls 160 and 162 into the interior 88 of thefirst furnace 76 for moving a carriage 170 (see FIG. 8 ) into and out ofthe interior 88 of the first furnace 76, in a manner discussed below.Infrared heaters 172 are provided on interior surface 174 of thesidewalls 160 and 162 (only sidewall 162 shown in FIG. 6 ), interiorsurface 176 of the ceiling 164, and the bottom wall 166 to heat theinterior 88 of the first furnace 76 to the desired temperature.Additionally, the first furnace comprises thermocouples 191 to measurethe heat of the furnace. Other devices, besides thermocouples, can beemployed to measure temperature of the furnaces.

The design and construction of the second furnace 78 is not limiting tothe invention and any type of furnace for heating a glass sheet to adesired temperature, e.g., but not limiting to the invention, a heatingtemperature above 900° F. for a lithium-soda-lime glass sheet, and aheating temperature above 1025° F. for a soda-lime-silica glass sheet.Heat temperatures for glass sagging are preferred, such as in the rangeof 1100° F. to 1250° F. For example, portions of the glass sheet to beshaped, e.g., but not limited to the shaped glass sheets 60 and 61 (seeFIG. 2 ) are heated to their higher shaping temperatures using microwaveenergy generated by a gyrotron, or any other suitable microwave energysource. With reference to FIGS. 5 and 6 , there is shown a deviceproducing ultra-high frequency, high-power electromagnetic waves 177,e.g., a gyrotron as shown, an optical box 178, and a mirror box 179mounted on roof or ceiling 184 of the second furnace 78. The operationof the gyrotron 177, optical box 178 and mirror box 179 are discussed ingreater detail below.

The second furnace 78 is similar in construction to the first furnace76, and includes a side wall 181 (see FIG. 6 ) and an opposite sidewall182 (see FIG. 5 ), a top wall or ceiling 184, and a bottom wall 186 (seeFIG. 6 ) to provide the interior 90 of the furnace 78. The stub rolls168 (see FIG. 6 ) extend through the sidewalls 180 and 182 into theinterior 90 of the second furnace 78 for moving the carriage 170 (seeFIG. 8 ) into and out of the interior 90 of the second furnace 78, in amanner discussed below. The infrared heaters 172 can be provided on aninterior surface 188 of the sidewalls 180 and 182 (the sidewall 181shown in FIG. 6 and the sidewall 182 shown in FIG. 5 ), interior surfaceof the ceiling 184 and the bottom wall 186 to heat the interior 90 ofthe second furnace 78 to a desired temperature. For alithium-aluminum-silicate glass sheets, the interior 90 of the furnace78 was heated to a temperature within the range of 600-900° F. and forsoda-lime-silicate glass sheets, the interior 90 of the furnace 78 washeated to a temperature within the range of 900-1000° F. Generally, butnot limiting to the invention, the preheat temperature of the furnace 76and the temperature of the furnace 78 with the gyrotron de-energized aresimilar such that the temperature attained by the glass sheets in thefurnace 76 is maintained in the furnace 78.

The temperature of the interiors 88 and 90 of the furnaces 76 and 78,respectively was measured by thermocouples 191. The thermocouples 191forward a signal to a computer microprocessor system 193 (see FIG. 9 ).The computer microprocessor system 193 acts on the signal to determinethe temperature of the interiors 88 and 90 of the furnaces 76 and 78,respectively. If the temperature of one or both of the furnace interiorsis (are) below a set temperature, a signal is forwarded along line 195to increase the heat input of the furnace. On the other hand, if thetemperature of one or both of the furnace interiors 88 and 90 is (are)too high, a signal is forwarded along the line 195 to decrease the heatinput to the furnace. If the temperature of the furnace interior is inan acceptable range no action is taken.

The conveyor system for the furnace 74 includes the stub conveyor rolls168 of the first furnace 76 driven by a gearing arrangement 192 (seeFIG. 5 ) including a shaft for rotating the stub rolls and a motor topower the shaft (the shaft and motor of the gearing arrangement 192 arenot shown), and includes the stub conveyor rolls 168 of the secondfurnace 78 driven by a gearing arrangement 194 (see FIG. 5 ) including ashaft for rotating the stub rolls and a motor to power the shaft, theshaft and motor of the gearing arrangement 194 are not shown. As isappreciated by those skilled in the art, conveyors using stub rolls arewell known in the art and no further discussion is deemed necessary.

With reference to FIGS. 3-8 , as needed, at a loading station (notshown) one or more glass sheets are positioned on a bending iron, e.g.,the bending iron 70 shown in FIG. 4 . Two glass sheets, e.g., the glasssheets 68 and 69 (see FIG. 3 ), are positioned on the bending iron 70,optionally ceramic dust (not shown) can be used to prevent sticking ofthe shaped glass sheets 60 and 61. The bending iron 70, having thesheets 68 and 69, is positioned on the carriage 170 (FIG. 8 ) and thecarriage 170 is placed on stub rolls 200 of a moveable conveyor 202. Themoveable conveyor 202 is moved from the loading area to the furnacearea. The door 92 of the first furnace 76 is opened (see FIGS. 5 and 6 )and the moveable conveyor 202 is moved into the opening 80 to align thestub rolls 200 of the moveable conveyor 202 with the stub rolls 168 ofthe first furnace 76. The carriage 170 is then moved into engagementwith adjacent stub rolls 168 of the first furnace 76, and the carriage170 is moved into the interior 88 of the furnace 76 by the stub rolls168 of the first furnace 76. The rotation of the stub rolls 168 isstopped when the carriage 170 is in the predetermined position in theinterior 88 of the first furnace 76, which is usually the hottestposition in the first furnace 76. After the rotation of the stub rolls168 stops, the carriage 170 having the bending iron 70 and the glasssheets 68 and 69 remains in the first furnace 76 until the glass sheets68 and 69 reach the desired temperature, e.g., the temperature for alithium-aluminum-silicate glass is within the range of 600-900° F., andthe temperature for a soda-lime-silica glass is within the range of900-1000° F. Optionally, the carriage 170 can be moved slightly upstreamand downstream along the conveyor movement path to circulate the heatedair in the furnace around the sheets 68 and 69.

The temperature of the glass sheets can be monitored in any convenientmanner, e.g., the temperature of the glass sheets 68 and 69 aremonitored by a an optical pyrometer, or an optical thermal scanner, suchas optical pyrometer or optical thermal scanner manufactured by LandInstruments International of Dronfield, UK (Land). A pyrometer orthermal scanner 204 is mounted on the roof 164 of the first furnace 76(see FIG. 5 ). More particularly, a pyrometer or thermal scanner 204,e.g., but not limited to an optical thermal scanner (made by Land),measures the temperature of the glass as the carriage 170 moves towardthe door 94 separating the furnaces 76 and 78. A signal is forwardedalong line 204 a to the computer microprocessor system 193 (see FIG. 9). If the temperature of the glass is within an acceptable preheattemperature range, e.g., at a temperature just below the temperature atwhich the glass sags, the carriage 170 is moved into the furnace 78. Ifthe glass is not within the acceptable shaping temperature range, thecarriage 170 is not moved into the shaping furnace 78 and appropriateaction, e.g., but not limited to, increasing the temperature of thefurnace 76 if the glass temperature is too low or decreasing thetemperature of the furnace 76 if the glass temperature is too high, istaken.

After the glass sheets 68 and 69 reach the desired temperature, the door94 of the second furnace 78 is opened, and the stub rolls 168 of thefirst furnace 76 and the second furnace 78 are energized to move thecarriage 170 through the opening 84 of the second furnace 78 to adesignated shaping position in the interior 90 of the second furnace 78,to be discussed in detail below. The door 94 of the second furnace 78can be closed at any time after the carriage 170 has passed into theinterior of the second furnace 78. After the carriage 170 having theglass sheets 68 and 69 and the bending iron 70 is positioned in thedesignated shaping position in the interior 88 of the second furnace 78,or the carriage 170 has cleared the door 94 as discussed below, the door94 is closed, and the shaping process of the invention using thegyrotron 177 discussed in detail below is practiced.

After the glass sheets 68 and 69 are shaped, the gyrotron 177 isde-energized or deactivated, and the door 94 of the second furnace 78 isopened. The stub rolls 168 of the first and the second furnaces 76 and78, respectively, are energized to move the carriage 170 having theshaped sheet 60 and 61 from the interior 90 of the second furnace,through the opening 84 of the second furnace 78 and into the interior 88of the first furnace 74. After the carriage 170 is moved into theinterior 88 of the first furnace 76, the door 94 of the second furnace78 is closed. The shaped glass sheets are controllably cooled to annealthe sheets. When the annealing process is completed, the door 92 of thefirst furnace 76 is opened and the moveable conveyor 202 (see FIG. 8 )is moved into the opening 80 of the first furnace 76 into alignment withthe stub rolls 168 of the first furnace 76. The stub rolls 168 of thefirst furnace are energized to move the carriage 170 out of the interior88 of the first furnace 76 onto the moveable conveyor 202. The moveableconveyor having the carriage 170 is moved to an unload station (notshown) and the shaped glass sheets are removed from the bending iron 70in any usual manner.

The discussion is now directed to using the gyrotron 177 (see FIGS. 5, 6and 10 as needed) to heat portions of one or more glass sheets to theirbending or shaping temperature. Of note, the present applicationdescribes the use of a gyrotron system. The gyrotron is a non-limitingexample and any suitable system that might be employed to spot-heat aglass sheet through a thickness of the sheet, including exteriorsurfaces and the interior of the sheet. Suitable systems include systemsthat produce ultra-high frequency, e.g., at least 20 GHz (gigahertz),and high-power, e.g., at least 5 kW (kilowatt) electromagnetic waveswithin the microwave spectrum. For example, such as a klystron or atraveling wave tube, though the output frequency and wattage of thesedevices are less than that of a gyrotron system. As previouslydiscussed, glass for aircraft transparencies are made using thecut-after-bend process to remove portions of the glass sheets havingoptical distortions, e.g., but not limiting thereto resulting from longperiods of time required for the glass sheets to rest on the bendingiron to attain the desired temperature for bending. For example, it isexpected that the overheating of the surface of the glass sheet usingtraditional methods, in order to achieve a desired bending of the glass,is rendered unnecessary by use of the gyrotron or other source ofhigh-energy electromagnetic radiation. Glass sheet surface temperaturecan be reduced by 30-40% using a gyrotron to internally heat selectedportions of the glass sheets to their bending or shaping temperature. Ascan now be appreciated, it is expected that the reduction of the need tooverheat the glass surface by traditional methods of regulating furnacetemperature, and the resultant elimination of overheating of the bendingirons and/or shaping rails on which the glass sheet sits, significantlyreduces glass marring, and greatly facilitates bending of glass sheetsfor, e.g., aircraft transparencies using the cut-to-size process insteadof the cut-after-bend process.

A gyrotron is a high-powered linear beam vacuum tube capable ofgenerating high-power, high-frequency electromagnetic radiationapproaching the edge of the infrared terahertz (THz) spectrum. Itsoperation is based on the stimulated cyclotron radiation of electronsoscillating in a strong magnetic field, e.g., as provided by asuperconducting magnet. Any suitable microwave generator capable ofgenerating high-power, high-frequency electromagnetic waves, such as amicrowave generator having an output frequency ranging from 20 GHz to300 GHz, and having a power output of at least 5 kW, would be suitable.A schematic, indicating the various parts of the gyrotron 177 is shownin FIG. 10 . In general and not limiting to the invention, in theoperation of the gyrotron 177, electrons that are emitted by a cathode206 surrounded by gun coil magnets 208, are accelerated in a strongmagnetic field of a superconducting magnet 210. While an electron beam212 travels through the intense magnetic field of magnet 210, theelectrons start to gyrate at a specific frequency given by the strengthof the magnetic field. In a cavity 214, located at the position with thehighest magnetic field strength, the THz radiation is stronglyamplified. Mode converter 216 is used to form free-gaussian beams 217that leave the gyrotron 177 through a window 222 and is coupled to awaveguide 224. The operation of gyrotrons is well known in the art andno further discussion is deemed necessary. Gyrotrons are commerciallyavailable from, e.g., Gyrotron Technology, Inc. of Philadelphia, Pa.

With continued reference to FIG. 10 , the free-gaussian beams 217 passthrough the waveguide 224 to the optical box 178. The optical box 178has mirrors (not shown) arranged as is known in the art to collimate thefree-gaussian beams 217 into a single beam 225 and control the size,e.g., the diameter, of the beam 225. The collimated beam 225 leaves theoptical box 178 through waveguide 226 and passes into the mirror box179. The mirror box 179 has one or more moveable mirrors 228 (one mirrorshown in phantom in FIG. 10 ) to move the beam 225 through apredetermined area defined by a cone 230 (see FIGS. 6 and 10 ). In FIG.10 , the beams 225 moving through the cone 230 are incident on the flatglass sheet, e.g., the flat glass sheets 68 and 69 positioned on abending iron, e.g., the bending iron 70 (FIG. 4 ). The sheets 68 and 69and the bending iron 70 are shown in block diagram in FIG. 10 .

The discussion is now directed to using the beam 225 from the gyrotron177 to heat portions 232 of the flat glass sheets 68 and 69 (see FIG. 3) that are shaped by an articulating arm 234 of the bending iron 70(FIG. 4 ) and portions 236 shaped by the fixed shaping rail 238 of thebending iron 70. In general, the flat glass sheets 68 and 69 positionedon the shaping rail 239 of the articulating arm 234 maintain thearticulating arm 234 in a down position as viewed in FIG. 4 , whichmaintains weight 240 in the up position. As the portion 232 of the glasssheets 68 and 69 overlaying the shaping rail 239 of the articulating arm234 of the bending iron 70 is heated to the shaping temperature of theglass sheets 68 and 69, the weight 240 moves downwardly, moving thearticulating arm 234 upwardly to shape the portion 232 of the glasssheet 68 and 69 to the shape 232 shown on the sheets 60 and 61 in FIG. 2. For a more detailed discussion of the operation of the articulatingarm 234 of the bending iron 70, reference should be made to USPA '494.The portions 236 of the flat glass sheets 68 and 69 are shaped by thefixed shaping rails 238 to the portions 236 of the shaped glass sheets60 and 61. In the practice of the invention, the portions 232 and 236 ofthe glass sheets 62 are heated by the beams 225 from the gyrotron 177 toquickly reach the bending temperature in the range of 1000 to 1100° F.for lithium-aluminum-silicate glass and in the range of 1100 to 1200° F.for soda-lime-silicate-glass.

The microprocessor or computer system 193 (FIG. 9 ) is programmed e.g.,but not limited to a signal sent along wire 239, to control theoperation of the mirrors of the optical box 178 to set the size of thebeam 225 incident on the portions of the glass sheets being shaped, themovement of the mirror 228 of the mirror box 179 to control thedirection of movement and speed of movement of the beam 225 in the zone230 (se FIG. 10 ), and the energy of the beam 225 by altering the anodevoltage, strength of the magnetic field and/or the voltage applied tothe system of the gyrotron. With reference to FIGS. 9 and 10 as needed,the mirror 228 operated by the microprocessor 193 moves the beam 225along a predetermined path 244 on surface 246 of the top glass sheet,e.g., top glass sheet 68 facing the mirror box 179. The energy beam 225as it moves along the path 244 in the area of the sheets designated bythe number 236, heats the glass sheets to their softening temperaturefor the glass sheets to take the shape of the fixed shaping rail 238(see FIG. 4 ). The energy beam 225 as it moves along the path 244 in thearea of the sheets designated by the number 232 (see FIG. 11 ) heats theglass sheets to their shaping temperature, at which time thearticulating arm 234 of the bending iron 70 shapes the sheets in thearea 232. Mounted through the roof 180 of the furnace 78 on each side ofthe mirror box 177 are pyrometers 250 (see FIG. 6 ) to monitor thetemperature of the glass. The pyrometers 250 are connected to themicroprocessor or computer 193 by wires 251 to send a signal to themicroprocessor 193, and the microprocessor forwards a signal along thewire 239 to maintain the temperature of the selected portions of theglass within a desired temperature range by altering the speed of thebeam 225 along the path 244 and/or by altering the energy of the beam asdiscussed above. More particularly, decreasing the speed of the beam 225increases the temperature of the glass and vice versa, and increasingthe anode voltage, the magnetic field, and/or the applied voltage,increases the temperature of the glass and vice versa.

The following is an example of the invention to shape a glass sheet foruse in the manufacture of an aircraft transparency. The flat glasssheets 68 and 69 (FIG. 3 ) are positioned on the bending iron 70 (FIG. 4). The bending iron 70 is placed in the carriage 170 (FIG. 7 ) and thecarriage is placed on the stub rolls 200 of the conveyor 202. Thecarriage 170 having the bending iron 70 and glass sheets 68 and 69 ismoved into the interior 88 of the first furnace 76 (FIG.6) by the stubrolls 168 of the first furnace 76. The glass sheets in the closedinterior of the first furnace 76 are heated to a temperature below thesoftening point temperature of the glass. Thereafter, the carriage 170having the heated glass sheets 68 and 69 is moved by the stub rolls 168of the first furnace 76 and the second furnace 78 into the interior 90of the second furnace 78 and positioned within the area of the cone 230(see FIGS. 6 and 10 ).

The temperature of the interior 90 of the second furnace 78 is generallythe same temperature as the interior 88 of the first furnace 76, i.e. atemperature below the shaping temperature of the glass sheets on thebending iron 70. At this temperature, the glass sheets positioned on thebending iron have not been shaped. After the carriage 170 positions thesheet within the cone 230, the gyrotron 177, the optical box 178, andthe mirror box 179, are energized to move the beam 225 along the scanpath 244 (see FIG. 10 ). As the beam 225 moves along the scan path 244,the gyrotron 177 is in a work mode. The energy beam 225 as it movesalong the path 244 in the area of the sheets designated by the number236, heats the glass sheets to their softening temperature for the glasssheets to take the shape of the fixed shaping rail 238 (see FIG. 4 ).The energy beam 225 as it moves along the path 244 in the area of thesheets designated by the number 232 (see FIG. 9 ) heats the glass sheetsto their shaping temperature, at which time the articulating arm 234 ofthe bending iron 70 shapes the sheets in the area 232. As the beam movesalong the segments 250 of the scan path, the beam is in the work mode toheat the segment 232 of the sheet 68. As the segment or portion 232 ofthe sheet 68 is heated the sheet segment softens and the weight 240 ofthe bending iron moves the articulating rail 238 upwardly to shape theportion 232 of the sheet 268. After the sheets are shaped, power to thegyrotron 177 is reduced or disconnected to put the gyrotron and beam 225in the idle mode.

The stub rolls 168 of the second and first furnaces 78 and 76,respectively, move the carriage 170 having the shaped sheets 60 and 61from the interior 90 of the second furnace 78 into the interior 88 ofthe first furnace 76. The shaped sheets in the first furnace 76 arecontrollably cooled to anneal the shaped glass sheets. Thereafter thecarriage 170 is moved by the stub rolls 168 of the first furnace 76 ontothe moveable conveyor 202, and the moveable conveyor moved to an unloadarea (not shown).

As can now be appreciated, care is exercised to make certain thecarriage 170 (see FIG. 9 ) is moved into the furnaces 76 and 78, andbetween the furnaces 76 and 78, when the doors 92 and 94 (see FIGS. 5and 6 ) are open. As a safety feature, tracking sensors 300, 302 and 304were used to track the position of the carriage 170 as it moved throughthe furnaces 76 and 78. Although not limiting to the invention, each ofthe tracking sensors 300, 302 and 304 included a generated continuouslight beam, e.g., but not limited to, a laser generated beam of lightincident on a detector. When the carriage 170 moved through thecontinuous light beam, the beam was directed away from the detector andthe detector sends a signal along a cable 306 to the microprocessor 193indicating that the light beam was not incident on the detector. Thecomputer microprocessor system 193 sends a signal along a wire 308 toopen or close the door 92 or the door 94. By way of illustration and notlimiting to the invention, the tracking detector 300 is positioned inthe furnace 76 spaced from the door 92 a distance greater than the widthof the carriage 170. The travel of the beam of light is transverse tothe path of travel of the carriage 170. As the carriage 170 moves intothe furnace 76, the carriage 170 interrupts the light beam by directingthe beam away from the detector of the sensor 300. The detector of thetracking sensor 300 sends a signal along the cable 306 to themicroprocessor 193 indicating that the light beam is not impinging onthe detector and the microprocessor sends a signal along cable 308 toenergize the motor 124 (see FIG. 5 ) to close the door 92.

Optionally, the glass sheets 68 and 69 are heated as the carriage 170moves through the furnace 76, or the glass sheets 68 and 69 are moved tothe center of the furnace and stopped to heat the sheets. After theglass sheets are heated, the glass sheets 68 and 69 (see FIG. 3 ) andthe carriage 170 are moved toward the door 94 separating the furnaces 76and 78. The carriage interrupts the light beam of the sensor 302 and asignal is forwarded along the cable 308 to computer microprocessorsystem 193 to energize the motor 145 to raise the door 94. The system istimed such that the carriage 170 can continuously move from the firstfurnace 76 into the second furnace 78 without any interruptions. Thecarriage 170 moves into the furnace 78 and after completely entering thefurnace 78 interrupts the light beam of the sensor 304. The sensor 304forwards a signal along cable 308 to the microprocessor193 to close thedoor 94; the microprocessor 193 forwards a signal along the cable 308 toenergize the motor to close the door 94. The carriage 170 is moved intothe shaping position and the conveyor stops. As can be appreciated thedistance from the shaping position to the beam of light of the detector304, and the speed of the carriage 170 are known, and in this fashionthe motion of the conveyor can be stopped when the carriage and theglass sheets are in the shaping position. In another example of theinvention, a tracking sensor 309 (shown in phantom and only shown inFIG. 6 ) is used to position the carriage 170 in the shaping position.As the carriage 170 displaces or interrupts the light beam of thetracking sensor 309, a signal is forwarded, e.g., along the cable 306 tothe computer microprocessor system 193 and the computer microprocessorsystem forwards a signal, e.g., along the cable 308 to stop the rotationof stud rolls to position the carriage 170 and the glass sheets in theshaping position. Optionally, the sensor 309 and the timing of thecomputer microprocessor system can be used for positioning the carriagerelative to the beams.

After the glass sheets 68 and 69 are shaped, the carriage 170 and theshaped sheets are moved out of the furnace 74. More particularly and notlimiting to the invention, the carriage 170 deflecting or interruptingthe light beam of the sensor 304 opens the door 94, interrupting thelight beam of the detector 302 closes the door 94, and interrupting thelight beam of the detector 300 opens the door 92.

As can be appreciated, the invention is not limited to the design of thefurnace 74, and the invention contemplates practicing the invention withany type of furnace such as, but not limited to the furnaces shown inFIGS. 5 and 6 discussed above, and FIGS. 12-15 discussed below. Moreparticularly, shown in FIG. 12 is a furnace 258 having the first andsecond furnaces 76 and 78, respectively, discussed above and a furnace260 attached to the second opening 86 of the second furnace 78 (seeFIGS. 5, 6 and 12 ). The furnace 260 is similar, if not identical, tothe first furnace 76. With the furnace arrangement shown in FIG. 12 ,the carriage 170 having the bending iron 70 having the sheets 68 and 69can move along the path designated by the arrow 270 through the furnace76 to preheat the glass sheets 68 and 69, through the furnace 78 toshape the glass sheet 68, and through the furnace 260 to anneal theshaped glass sheets 60 and 61 as discussed above for the first furnace76. In a second example of the invention, the furnace 258 can shape theglass sheets 68 and 69 using the first and second furnaces 76 and 78,respectively, as discussed above by moving the carriage 170 having thebending iron 70 and the glass sheets 68 and 69 along a reciprocatingpath designated by the arrow 272 and shaping second group of glasssheets 68 and 69 using the furnaces 78 and 260 in a similar manner asthe furnaces 76 and 78, and moving the second group of glass sheetsalong a reciprocating path designated by the arrow 274.

With reference to FIG. 13 , there is shown another example of a furnacedesignated by the number 261. The furnace 261 includes the furnaces 76,78 and 260 (see FIG. 12 ) and furnaces 262 and 264. The shaping furnace78 is between the furnaces 262 and 264. The glass processed using thefurnace 261 has paths of travel 270 and 278 in the horizontal directionand paths of travel 270 a and 278 a in the vertical direction, as viewedin FIG. 13 ; the reciprocal paths of travel 272 and 274, and reciprocalpaths of travel 275 and 276 in the vertical direction as viewed in FIG.13 . The glass sheets moving along the path of travel 276 can move intoand out of the furnaces 262 and 78, and the furnaces 264 and 78. As canbe appreciated, the conveying system for the furnace 78 shown in FIG. 13is adjustable or provided with a two tier conveying system to move thecarriage along the path 278 through the furnaces 262, 78 and 262, and tomove the carriage along the path 278 a through the furnaces 76, 78 and260.

With reference to FIG. 14 , there is shown still another non-limitingembodiment of a furnace of the invention designated by the number 280.The furnace 280 includes a first tunnel furnace 282 to preheat the flatglass sheets 68 and 69 as they move in the direction of the arrow 284.The glass sheets 68 and 69 can be positioned on the bending iron 70, oras discussed above, the bending iron 70 can be positioned in thecarriage 170. Shaping furnace 286 positioned at exit end 287 of thetunnel furnace 282 can have any number of gyrotrons to provide anynumber of shaping zones, e.g., one shaping zone 230 shown in solid line,or two shaping zones 231 shown in phantom, or three shaping zones shownin solid line 230 and phantom 231. A second tunnel furnace 288 isconnected to exit end 289 of the shaping furnace 286 to controllablycool the shaped glass sheets 60 and 61. Additionally depicted arethermal sensor 324 and positional sensors 320 and 321.

Thermal sensor 324 is any sensor or scanning device, such as an IRscanner or IR imaging sensor, able to produce data representing thetemperature of one or more portions of a glass sheet, such as acharged-coupled device (CCD), an infrared laser-light sensor device, athermal imaging device or a thermal scanner, as are broadly known andcommercially available. Representations of a glass sheet can be producedby a computer implemented process, by assembling data, such as raw CCDdata, obtained from the thermal sensor, and producing a two-dimensionalor three-dimensional temperature profile of at least a portion of theglass sheet. As indicated below, the thermal data obtained from thethermal sensor, and the temperature profile produced from that data iscompared to a reference temperature profile in a computer-implementedprocess, and any differences between the produced temperature profileand the reference temperature profile are triggers selective heating ofthe glass sheet by the gyrotron to match the temperature profile of theglass sheet with that of the reference temperature profile.Computer-implemented processes to perform these tasks, as well as anytask indicated herein are readily devised and implemented by those ofordinary skill in the computer imaging and process control arts. One ormore thermal sensors can be used, and more than one different type ofsensor may be employed to obtain an accurate and useful real-timethermal profile of a glass sheet.

Positional sensors 320 and 321 are any device able to produce datarepresenting the shape of a glass sheet. Non-limiting examples ofpositional sensors are CCDs and laser-light sensors, as are broadlyknown and commercially available. Data is obtained from the positionalsensors 320 and 321 and is assembled by a computer-implemented processto produce a shape profile of a glass sheet in the furnace 78. Asindicated below, the positional data obtained from the positionalsensor, and the shape profile produced from that data is compared to areference shape profile in a computer-implemented process, and anydifferences between the produced shape profile and the reference shapeprofile triggers selective heating of the glass sheet by the gyrotron tomatch the shape profile of the glass sheet with that of the referenceshape profile. Any number of positional sensors can be used, so long asmeaningful data is obtained relating to the real-time shape profile ofthe glass sheet during the bending process. Likewise, more than one typeof positional sensor can be used to obtain the produced shape profile soas to obtain an accurate and useful real-time representation of theglass sheet during the bending process. For example, two CCDs may beused to generate a stereoscopic shape profile of a glass sheet, whileone or more laser distance sensor is used to determine the spatiallocation or orientation of one or more points on the surface of theglass sheet in order to best determine the degree of bending of theglass sheet at any time.

The obtaining and processing of thermal and shape data, and the use ofthose data to produce temperature and shape profiles may be repeated oneor more times during the bending process, e.g., at intervals rangingfrom every 0.0001 to 60 seconds, including every 0.0001, 0.001, 0.01,0.1, 0.5, 1, 2, 5, 10, 15, 20, 30 and 60 seconds including any incrementtherebetween. Even shorter time intervals are contemplated, and are onlylimited by the throughput (e.g., processing power) of the computersystem. The gyrotron system may not be able to respond to the computersystem as quickly as the computer system can analyze data, so scanningintervals may be set based on the responsiveness of the gyrotron system.That said, the scanning and analyzing of thermal and optionally spatialprofiles can be performed at faster rates than the controlling of thegyrotron, within limits of the pertinent hardware.

As is appreciated by those skilled in the art, during the shaping of thesheets, the entrance opening 290 of the first tunnel furnace 282 and theexit opening 292 of the second tunnel furnace 288 can remain open. Thedoors to enter and leave the shaping furnace 286 are preferably openedto move the glass sheets to be shaped into and out of the furnace 288,and during the shaping of the glass sheets in the shaping furnace 286,the doors (see FIGS. 5 and 6 ) are closed to minimize heat loss duringthe sheet shaping process. Optionally and within the scope of theinvention, the doors of the tunnel furnace can remain open forcontinuous movement of the glass sheets through the tunnel furnace toshape the glass sheets.

FIG. 15 shows schematically an example of the furnace system of FIG. 6 .Details of FIG. 6 that are unnecessary to show operational andstructural differences between the furnace of FIG. 6 and that of FIG. 15are omitted for ease of visualization, but are included in FIG. 15 . Asin FIG. 6 , the furnace system 74 of FIG. 15 includes a first chamber76, a second chamber 78, and a door 94 supported by a U-shaped member136. The first chamber 76 preheats, through the use of infrared heaters,a glass sheet carried on conveyor 202, to a temperature within the rangeof 900-1000° F., although other suitable preheat temperatures may beutilized depending on the material of the glass sheet. In use, the glasssheet is supported or positioned on a bending iron (not shown, but asdepicted and described herein). The second chamber 78, also hereinreferred to as a shaping chamber, selectively heats portions of the flatglass sheets to achieve a desired shape of the glass sheet. Infraredheaters of the second chamber 78 maintain the temperature of the chamberto about 1000-1100° F., or any temperature just below a shaping or sagtemperature of the glass sheet. Specific portions of the sheet of glassare selectively heated in the second chamber 78 by a gyrotron beamsystem, including a gyrotron 177, an optical box 178, and a mirror box179. A benefit of the use of a high-energy microwave system describedherein is that the microwave source, e.g., gyrotron, heats the glasssheet internally, and at precise locations on the glass sheet. On theother hand, traditional infrared heaters heat only the glass surface andthrough heat conduction, the energy passes into the glass. As a result,under traditional infrared heating the glass surface is significantlyhotter than the internal glass temperature, hence increasing thelikelihood of undesirable manufacturing conditions for glass bending. By“selective heating” it is meant that, the gyrotron beam system isdirected to heat specific areas, portions, or locations of the glass tocause the glass sheet to sag, to produce a desired shape. Once the glasssheet is shaped to a desired specification, it is controllably cooled.In the embodiment shown, the first chamber 76 also serves as a coolingchamber for annealing the glass sheet, such that once the glass sheet isshaped in the second chamber 78, it is returned to the first chamber 76,where it is cooled in a controlled manner. The furnace system 74 caninclude a third chamber on an opposite side of the second chamber 78from the first chamber 76, and the conveyor 202 passes the glasssequentially from the first chamber 76, through the second chamber 78,to the third furnace. The furnace system 280 of FIG. 14 depicts ananalogous orientation. Inclusion of a third furnace may simplify theprocess in that the glass sheet is able to move through the system in alinear manner. The third furnace is a cooling chamber which is able tocontrollably cool the shaped glass sheet to anneal the shaped glasssheet. The third furnace may be modified such that the shaped glasssheet can be thermally tempered or heat strengthened.

In addition to, or in lieu of, the pyrometer 204 shown in FIG. 6 , aninfrared sensor 324 can be provided. The pyrometer 204 and/or theinfrared sensor 324 monitor the temperature of the whole sheet of glassand/or specific portions of the glass. As used herein, a “portion” is anamount less than a whole or 100% of an object and can be a point, line,area, region, etc. on and/or in an object, such as a glass sheet.

The methods and systems described herein in one aspect rely on acomputer, for example like, but not limited to, a microprocessor 193, atleast for monitoring and controlling progress of the heating and bendingof the glass sheets described herein. A computer or computer system cantake any physical form, such as a personal computer (PC), credit-cardcomputer, personal digital assistant (PDA), smartphone, tablet,workstation, server, mainframe/enterprise server, etc. The termscomputer, computer system, or microprocessor system, or computermicroprocessor system are herein used interchangeably. A computerincludes one or more processors, e.g., a central processing unit (CPU),which carries out instructions for the computer. A computer alsoincludes memory, e.g., RAM and ROM (storing, e.g., the UEFI or BIOS),connected to the processor by any suitable structure such as a systembus. Computers also comprise non-transient storage for storingprogramming and data, in the form of computer readable medium/media,such as a hard drive, a solid state drive (SSD), an optical drive, atape drive, flash memory (e.g., a non-volatile computer storage chip), acartridge drive, and control elements for loading new software. Computersystems as described herein are not limited by any topology or by therelative location of the various hardware elements, recognizing thevaried physical and virtual structures those of ordinary skill employ inimplementing a computer system.

Data, protocols, controllers, software, programs, etc., may be storedlocally in the computer, e.g., in a hard drive or SSD; within a local orwide-area network, e.g., in the form of a server, a network associateddrive (NAS); or remotely, such that connection is made over an internetconnection, e.g., via remote access. Data, such as images, temperatureprofiles or shape profiles produced or used by the methods and systemsdescribed herein may be organized on computer readable media in adatabase, which is an organized collection of data for one or morepurposes. Other exemplary hardware that form elements of a typicalcomputer, include input/output devices/ports, such as, withoutlimitation: Universal Serial Bus (USB), SATA, eSATA, SCSI, Thunderbolt,display (e.g., DVI or HDMI) and Ethernet ports, as are broadly known,and graphics adaptors, which may be an integral part of the CPU, asubsystem of the motherboard, or as separate hardware device, such as agraphics card. Wireless communications hardware and software, such asWi-Fi (IEEE 802.11), Bluetooth, ZigBee, etc. may also be included in thecomputer. Elements of a computer need not be housed within the samehousing, but can be connected to a main computer housing via anysuitable port/bus. In a typical computer, at least the CPU, memory (ROMand RAM), input/output functionality, and often a hard drive or SSD anda display adaptor are housed together and are connected by ahigh-performance bus of any useful topology.

The computer, having storage and memory capabilities, can includecontroller aspects that allow for the design, storage, and execution ofinstructions, executable for independently or collectively instructingthe computer system to interact and operate as programmed, referred toherein as “programming instructions”. In the context of computing, acomputer-implemented process (i.e., program), broadly speaking, refersto any computer-implemented activity that generates an outcome, such asimplementation of a mathematical or logical formula or operation,algorithm, etc.

One example of a controller is a software application (for example,basic input/output system (BIOS), unified extensible firmware interface(UEFI), operating system, browser application, client application,server application, proxy application, on-line service providerapplication, and/or private network application) installed on thecomputer system for directing execution of instructions. In one example,the controller is a WINDOWS™—based operating system. The controller maybe implemented by utilizing any suitable computer language (e.g., C\C++,UNIX SHELL SCRIPT, PERL, JAVA™, JAVASCRIPT, HTML/DHTML/XML, FLASH,WINDOWS NT, UNIX/LINUX, APACHE, RDBMS including ORACLE, INFORMIX, andMySQL) and/or object-oriented techniques.

The controller can be embodied permanently or temporarily in any type ofmachine, component, physical or virtual equipment, storage medium, orpropagated signal capable of delivering instructions to the computersystem. In particular, the controller (e.g., software application,and/or computer program) may be stored on any suitable computer readablemedia (e.g., disk, device, or propagated signal), readable by thecomputer system, such that if the computer system reads the storagemedium, the functions described herein are performed.

The computer contains a “protocol”, that is instructions and data thatcontrol e.g., the bending process for a glass sheet. Various modelingtechniques may be used to develop protocols and may be implemented aspart of a computer-implemented protocol. Modeling techniques includescientific and mathematical models, specific for glass bendingprocesses, which are able to determine the required temperatures atdifferent stages of the process necessary to achieve a final glass sheetof high-quality. For example, the preheat temperature at the exit of thefirst furnace, glass forming/bending temperature profile in the glassforming furnace, exit glass temperature once the forming process iscomplete, and the glass annealing temperature. The protocol controls thegyrotron beam system to establish a heating profile to achieve aspecific shape for a glass sheet. A gyrotron beam can be manipulated invarious ways, such as, altering the path, speed, width, shape,frequency, dwell time at a location (position on the glass sheet), orintensity/energy (e.g., kilowatts, kW) of the gyrotron beam. In oneembodiment, beam width, beam shape, intensity/energy and frequency isconstant, but the location, path, speed and/or dwell time at a locationof gyrotron beam are altered to provide a desired heating profile on thesheet. In another example, the gyrotron beam's electrical power can bemanipulated, while the beam is moving at a constant speed across thesurface of the glass sheet to produce desired heat profile. In anotherexample, one can change both the electrical power and beam speed toachieve the same effect. The protocol comprises instructions at leastfor controlling any or all possible parameters of the gyrotron beam,such as: location, path, intensity/energy, speed, beam shape, beamdiameter, and output frequency, which may be controlled by the gyrotronunit or the post-gyrotron optics. As such, a protocol controls theheat-profile and/or heat distribution on a glass sheet for attaining adesired shape and size of the sheet of glass. Included as part of theprotocol, the computer receives and processes real-time data from thethermal and positional sensors, particularly the thermal sensor and,optionally the positional sensor. The computer then produces atemperature profile, and optionally a shape profile from the real-timedata. The temperature profile and shape profile are merelyrepresentations in the computer that can be compared to referencetemperature and shape profiles stored in association with the bendingprotocol. The computer system compares produced profiles to thereference profiles to determine differences between the producedprofiles and the reference profiles at one or more locations on theglass sheet, and, if differences are present and one or more positionson the glass sheet require heating to match the temperature and shape ofthe glass sheet to the reference profiles, the computer controls one ormore parameters of the gyrotron beam to selectively heat a portion ofthe glass sheet to correct those differences. In addition to the above,optionally, the computer receives additional temperature data from oneor more temperature sensors, such as thermocouples or IR scanners of oneor more chambers and/or furnaces of the system according to any examplesdescribed herein, and acts as a thermostat, monitoring and adjusting theambient temperature of the chamber, e.g., by adjusting the output of IRheaters, blowers, etc. utilized in the system. For example, in oneaspect, thermocouples (e.g., as shown in FIG. 6 ) detect the temperatureof the second furnace 78, as shown in FIG. 15 . If the second furnace 78is not at the desired temperature, the computer, usingcomputer-implemented processes for example as described above, comparesthe actual ambient temperature of the second furnace 78 to a storedreference ambient temperature for the second furnace 78, andautomatically adjusts the heat of the second furnace 78 in order toreach the stored reference ambient temperature. By “ambient temperature”in reference to the furnaces described herein, it is meant thetemperature of the atmosphere at one or more points within the furnace,and does not refer to the temperature of the glass sheet.

In another aspect, the thermal sensor 324 is an IR laser-light sensorthat captures an IR image of the glass sheet being bent, which is sentto the computer, which compares the captured image to a reference imagestored as part of a glass bending protocol for the particular glasssheet, and, if a position on the glass is at a temperature lower thanthat of the same position in the image stored as part of a glass bendingprotocol, the gyrotron beam is directed to heat that position until thetemperature of the position matches the reference temperature of theimage stored as part of a glass bending protocol. As used herein, aprotocol for producing a specific shape from a glass sheet contains oneor more reference temperature distribution profiles and shape profilesfor the specific shape and glass sheet at one or more time points duringthe bending process.

FIG. 15 also depicts optional positional sensors 320. A suitable lightsource to provide illumination of the glass sheet to the extentnecessary to permit imaging also may be employed, though heated glasstypically emits enough light for imaging purposes. The positionalsensor(s) comprises a single unit or multiple units that allow foreither image capture or capture of data in real time, indicating thespatial position of one or more positions on the glass sheet. Anon-limiting example is a positional sensor obtained from RockwellAutomation (Allen Bradly), for example, the 42CM 18 mm LaserSight or the42EF LaserSight RightSight are suitable positional sensors. Thepositional sensor can be an imaging sensor, such as one or more CCDand/or laser-light sensor devices housed either together or at separatelocations within the chamber 78. CCD and/or laser-light sensor devicessensor devices output 2D images that are processed within the computeror within the device. The images can be used in their 2D form, or can beprocessed to form a 3D image by the computer to produce a profile of theglass sheet that indicates the real-time spatial position and shape ofany portion or point on the glass sheet, and then compares that 2Dprofile to a reference profile associated with the protocol, and adjustsheating with the gyrotron beam to match the shape profile of the glasssheet with the reference profile. A large variety of position, distance,measurement, displacement, profile, 2D, and 3D sensors, e.g., lasersensors, are commercially available, for example and without limitationfrom Rockwell Automation (Allen Bradly), Emerson Electric of St. LouisMo., Schmitt Industries, Inc. of Portland Oreg., and Omron Automation &Safety of Hoffman Estates, Illinois. In any case, the positional sensoris connected to the computer, and data obtained from the positionalsensor, optionally in coordination with the IR data described above, andthat data is compared to reference data associated with a protocol forbending a particular glass sheet, and the temperature of any portion ofthe glass sheet can be adjusted using the gyrotron beam.

As shown in FIG. 15 , two positional sensors 320, 321, are shown. Acomposite 3D image or set of images of the glass sheet at any given timepoint can be generated by a computer implemented process so as toevaluate the shape of the glass sheet at any time point. The computersystem generated 3D image, composite image, or set of images of theglass sheet and/or a portion thereof can be compared to values of thereference shape profile of the protocol, and if a deviation from thedesired shape stored in the protocol is present, the computer systemcontrols the gyrotron 177 and/or ambient temperature of the secondfurnace 78, optionally in combination with infrared image data from the2D infrared imaging sensor 324 to heat the glass sheet, or portionsthereof, to shape the glass sheet to meet the requirements of therecipe. FIG. 16 provides a flowchart illustrating a non-limitingembodiment of the methods described herein employing two or threechambers as discussed in relation to FIG. 15 .

A gyrotron beam can be manipulated in various ways, such as, alteringthe path, speed, width, frequency, dwell time at a location, or energyintensity or electrical power of the gyrotron beam. In one example, beamwidth, energy and frequency is constant, but the location, path, speedand/or dwell time at a location of gyrotron beam are altered to providea desired heating profile on the sheet.

A “temperature profile” or “temperature distribution profile” refers tothe temperature of any portion or portions of a specific glass sheet atany time point or points during the process of heating, bending andcooling that sheet of glass. As used herein, a “reference temperatureprofile” refers to a temperature distribution profile for any specificglass sheet stored locally in or remotely from the computer system inassociation with a protocol for bending that specific glass sheet. Thereference temperature profile is created or developed by any method,such as by formula and/or trial-and-error, to produce a specific shapeof the specific glass sheet. The reference temperature distributionprofile for producing a desired shape from a glass sheet will depend ona variety of factors, including, among other factors: the composition ofthe glass sheet, the desired shape, and the bending iron shapes andfunctionality. By using a predetermined temperature profile as areference, and ultimately manipulating the gyrotron system toselectively heat the sheet of glass, an even glass viscositydistribution is produced not only inside of the glass, but throughoutthe glass. This even distribution of glass viscosity eliminatesoverheating of the glass surface and as a result, the glass sheet willbe formed or bend into required shape with a satisfied optical quality.

The terms “shape profile” refers to the 2D or 3D shape of a glass sheetat any time point or points during the process of heating, bending andcooling a sheet of glass. A “reference shape profile” refers to a shapeprofile for any specific glass sheet for any time point in the glassforming process stored locally in or remotely from the computer systemin association with a protocol for bending that specific glass sheet.The reference shape protocol is created or developed by any method, suchas by formula and/or trial-and-error, to produce a specific shape of thespecific glass sheet. As with the predetermined heat distribution, thereference shape profile for producing a desired shape from a glass sheetwill depend on a variety of factors, including, among other factors: thecomposition of the glass sheet, the desired shape, the bending ironshapes and functionality.

The invention further contemplates the use of safety equipment to limitor prevent damage to the persons operating the equipment, and/or toprevent or limit damage to the equipment. For example and not limitingto the discussion, the equipment includes an arc detector 330. The arcdetector 330 is mounted in the furnace 78 and included a photocellconnected to the microprocessor 193 by way of the cable 306. The arcing,as is known in the art, is ionized matter, e.g., but not limited to anair born pocket of dust and appears as a burst of light. The arcingphenomenon is well known in the art and no further discussion is deemednecessary. The photocell of the detector 330 senses the arcing andforwards a signal along the cable 305. The microprocessor 193 forwards asignal along the cable 308 to shut the gyrotron down to prevent damageto the personnel around the furnace 78 and to the gyrotron equipment.

The examples of the invention were discussed to shape two glass sheets.As can now be appreciated, the invention is not limited thereto and theinvention can be practiced on one sheet, or more than two sheets, e.g.,but not limited to three, four or more sheets.

The invention can be further characterized in the following numberedclauses.

Clause 1: A method of shaping a glass sheet comprising:

-   a. preheating the glass sheet on a bending iron (70) to a preheating    temperature ranging from 600° F. to 1000° F.;-   b. increasing the temperature of the sheet to a temperature ranging    from greater than the preheating temperature to less than a    temperature at which the glass sags; and-   c. bending the glass sheet by:    -   i. selectively heating a portion of the glass sheet with a        device (177) that produces ultra-high frequency, high-power        electromagnetic waves controlled by a computer-implemented        protocol to a temperature at which at least a portion of the        glass sheet sags;    -   ii. scanning at least the portion of the glass sheet with one or        more thermal sensors (324) at one or more time points during or        after the selectively heating step and obtaining from data        obtained from the one or more thermal sensors (324) a        temperature distribution in at least two dimensions for at least        the portion of the glass sheet;    -   iii. comparing, using a computer-implemented process the        obtained temperature distribution to a reference temperature        distribution of the computer-implemented protocol; and    -   iv. selectively heating the glass sheet with a beam (225) of the        device (177) that produces ultra-high frequency, high-power        waves controlled by the computer-implemented process to match        the obtained temperature distribution with the reference        temperature distribution of the computer-implemented protocol.

Clause 2: The method of clause 1, wherein the device (177) producingultra-high frequency, high-power electromagnetic waves is a gyrotron.

Clause 3: The method of clause 1 or clause 2, further comprisingrepeating steps ii. through iv. of the bending step c. until theobtained temperature distribution matches the reference temperaturedistribution of the computer-implemented protocol.

Clause 4: The method of any one of clauses 1 to 3, in which the bendingstep c. further comprises:

-   -   v. obtaining positional data of at least the portion of the        glass sheet from one or more positional sensors (320, 321) at        the one or more time points during the selective heating step        and producing a shape profile using the computer-implemented        process for the glass sheet at the one or more time points;    -   vi. comparing, using the computer-implemented process, a        produced shape profile to a reference shape profile of the        computer-implemented protocol; and    -   vii. selectively heating the glass sheet with the beam (225) of        the ultra-high frequency, high-power device (177) controlled by        the computer-implemented process to match the shape profile of        the glass sheet to the reference shape profile.

Clause 5: The method of clause 4, further comprising repeating steps v.through vii. of the bending step c. until the obtained shape profilematches the reference shape profile of the computer-implementedprotocol.

Clause 6: The method of clause 4 or clause 5, wherein comparing stepsiii. and vi. are performed substantially concurrently.

Clause 7: The method of any of clauses 4 to 6, in which one or more ofthe positional sensors (320, 321) is a camera or charge-coupled device(CCD).

Clause 8: The method of clause 7, wherein the shape profile is athree-dimensional shape profile assembled from data obtained from aplurality of CCDs.

Clause 9: The method of clause 7, wherein the shape profile is athree-dimensional shape profile assembled from data obtained from aplurality of laser-light sensors.

Clause 10: The method of any of clauses 4 to 9, wherein one or more ofthe one or more positional sensors (320, 321) are laser-light sensors.

Clause 11: The method of any of clauses 1 to 10, wherein the glass sheetis cut-to-size prior to heating and shaping.

Clause 12: The method of any of clauses 1 to 11, in which the thermalsensor (324) is an IR scanner or an IR imaging sensor, optionally thelaser-light sensor.

Clause 13: A system comprising: a first furnace (76) comprising infraredheaters (172) and temperature sensors (191); and a second furnace (78)comprising the infrared heaters (172), a device that produces ultra-highfrequency, high-power electromagnetic waves (177), and an optical systemfor controlling shape, location, and movement of a beam of the device toa glass sheet on a bending iron (70) within the second furnace (78), andone or more infrared (IR) imaging sensors; a conveyor system forcarrying the glass sheet on the bending iron (70) through the first andsecond furnaces (76, 78); a computer system connected to the one or moreIR imaging sensors and the ultra-high frequency, high-power device(177), comprising a processor and instructions for controlling bendingof the glass sheet in the second furnace (78) by selective heating bythe ultra-high frequency, high-power device (177), the instructionscomprising a computer-implemented protocol for heating and bending theglass sheet in the second furnace (78), wherein the computer systemobtains a temperature profile of the glass sheet at one or more timepoints during the bending of the glass from the one or more IR imagingsensors (324), compares the obtained temperature profile to a referencetemperature distribution of the computer-implemented protocol, andcontrols the ultra-high frequency, high-power device (177) toselectively heat the glass sheet to match the reference temperaturedistribution; and a third heating furnace (260) to controllably cool theglass sheet, comprising IR heaters, a forced cool air convection system,and air fans.

Clause 14: The system of clause 13, wherein the device producingultra-high frequency, high-power electromagnetic waves (177) is agyrotron.

Clause 15: The system of clause 13 or clause 14, further comprising oneor more positional sensors (230 and 231) in the second furnace (78)arranged to obtain positional data for one or more portions of the glasssheet during bending, wherein the positional sensors (230 and 231) areconnected to the computer system, wherein the computer system:

-   a. obtains data from the one or more positional sensors (230, 231)    at one or more time points during the bending of the glass sheet;-   b. produces a shape profile for the glass sheet from the obtained    data from the one or more positional sensors at the one or more time    points;-   c. compares the obtained shape profile to a reference shape profile    of the computer-implemented protocol; and-   d. controls the ultra-high frequency, high-power device (177) to    selectively heat the glass sheet to match the shape profile of the    glass sheet to the reference shape profile.

Clause 16: The system of clause 15, wherein one or more of the one ormore positional sensors (230, 231) is a charge-coupled device (CCD).

Clause 17: The system of clause 16, comprising a plurality of CCDs,wherein the shape profile is a three-dimensional shape profile assembledfrom data obtained from the plurality of CCDs.

Clause 18: The system of any of clauses 15 to 17, wherein one or more ofthe one or more positional sensors (230, 231) are laser-light sensors.

Clause 19: The system of clause 18, comprising a plurality of thelaser-light sensors, wherein the shape profile is the three-dimensionalshape profile assembled from data obtained from the plurality of CCDs.

Clause 20: The system of any of clauses 13 to 19, wherein one or more ofthe one or more IR imaging sensors (324) is a laser-light sensor or aCCD.

Clause 21: The system of any of clauses 13 to 20, further comprising thethird furnace (260) having the IR heaters, and wherein the conveyorsystem further carries the glass sheet through the third furnace.

Clause 22: The system of clause 21, wherein the first, second and thirdfurnaces (76, 78, 260) form a single tunnel.

Clause 23: The system of clause 22, comprising doors between the firstand second furnaces (76, 78) and between the second and third furnaces(78, 260).

Clause 24: The system of any of clauses 13 to 23, in which the computersystem obtains a temperature of the first furnace and adjusts thetemperature of the first furnace (76) using the IR heaters to match apreheating temperature according to the computer-implemented protocol.

Clause 25: The system of any of clauses 13 to 24, in which the computersystem obtains an ambient temperature of the second furnace (78) andadjusts the temperature of the second furnace (78) using the IR heatersto match a temperature ranging from greater than the preheatingtemperature to less than a temperature at which the glass sags.

It will be readily appreciated by those skilled in the art thatmodifications can be made to the non-limiting embodiments of theinvention disclosed herein without departing from the concepts disclosedin the foregoing description. Accordingly, the particular non-limitingembodiments of the invention described in detail herein are illustrativeonly and are not limiting to the scope of the invention, which is to begiven the full breadth of the appended claims and any and allequivalents thereof.

1. (canceled)
 2. A furnace system, comprising: a first chambercomprising at least one first infrared heater and at least one firstthermal sensor; a second chamber comprising: at least one secondinfrared heater, a device that produces ultra-high frequency, high-powerelectromagnetic waves, an optical system for controlling shape,location, and/or movement of a beam of the device to a glass sheet on abending iron within the second chamber, at least one second thermalsensor, and at least one positional sensor in the second chamber toobtain positional data for at least one portion of the glass sheetduring bending; a conveyor system for carrying the glass sheet on thebending iron through the first and second chambers; and a computersystem connected to the at least one second thermal sensor, the at leastone positional sensor, and at least one of the device that producesultra-high frequency, high-power electromagnetic waves or the opticalsystem, the computer system comprising one or more processors programmedor configured to control selective heating by the device that producesultra-high frequency, high-power electromagnetic waves to heat and bendthe glass sheet in the second chamber, wherein the one or moreprocessors are further programmed or configured to: obtain a temperatureprofile of the glass sheet at a plurality of time points during bendingof the glass sheet in the second chamber from the at least one secondthermal sensor; obtain data from the at least one positional sensor atthe plurality of time points during the bending of the glass sheet inthe second chamber; produce a shape profile for the glass sheet from theobtained data from the at least one positional sensor at the pluralityof time points; concurrently compare the obtained shape profile to areference shape profile and compare the obtained temperature profile toa reference temperature distribution; and during the bending of theglass sheet, control the device that produces ultra-high frequency,high-power electromagnetic waves to selectively heat the glass sheet tomatch the shape profile of the glass sheet to the reference shapeprofile and to match the obtained temperature profile of the glass sheetwith the reference temperature distribution.
 3. The system of claim 2,wherein the device producing ultra-high frequency, high-powerelectromagnetic waves is a gyrotron configured to produce waves with afrequency of at least 20 GHz and power of at least 5 kW.
 4. The systemof claim 2, wherein the at least one first thermal sensor or the atleast one second thermal sensor comprise at least one of an infrared(IR) scanner, an IR imaging sensor, a charged-coupled device (CCD), anIR laser-light sensor device, a thermal imaging device, or a thermalscanner.
 5. The system of claim 2, wherein the first chamber comprises afirst tunnel furnace comprising: a first entrance end and a first exitend; a first heating system comprising the at least one first infraredheater configured to heat the glass sheet passing through the firsttunnel furnace to a first predetermined temperature, and a first portionof the conveying system configured to move the glass sheet through thefirst tunnel furnace from the first entrance end toward the first exitend.
 6. The system of claim 5, wherein the second chamber comprises ashaping furnace, comprising: a second entrance connected to the firstexit end and a second exit end, and a mirror system to direct the devicethat produces ultra-high frequency, high-power electromagnetic waves toa predetermined area within the shaping furnace to shape a predeterminedportion of the glass sheet passing through the shaping furnace.
 7. Thesystem of claim 6, further comprising a third chamber, which comprisesanother tunnel furnace, the third chamber comprising: a third entranceend connected to the second exit end and a third exit end; a heatingsystem to controllably cool the shaped glass sheet passing through thethird chamber, and a third portion of the conveying system to move theglass sheet through the third chamber from the third entrance end towardthe third exit end.
 8. The system of claim 7, wherein the third chambercools the glass sheet directly after the bending of the glass sheet inthe second chamber, and wherein, directly after the bending of the glasssheet in the second chamber, the third portion of the conveyor systemcarries the glass sheet through the third chamber.
 9. The system ofclaim 7, wherein the first chamber, the second chamber, and the thirdchamber form a single tunnel.
 10. The system of claim 7, furthercomprising doors between the first chamber and the second chamber anddoors between the second chamber and the third chamber.
 11. The systemof claim 2, wherein, after the bending of the glass sheet in the secondchamber according to the reference temperature distribution, theconveyor system removes the glass sheet from the second furnace and theglass sheet is cooled.
 12. The system of claim 2, wherein the at leastone positional sensor comprises at least one charge-coupled device(CCD).
 13. The system of claim 2, wherein the at least one positionalsensor comprises a plurality of charge-coupled devices (CCD), andwherein the shape profile is a three-dimensional shape profile assembledfrom data obtained from the plurality of CCDs.
 14. The system of claim2, wherein the at least one positional sensor comprises a laser-lightsensor.
 15. The system of claim 2, wherein the at least one positionalsensor comprises a plurality of the laser-light sensors, and wherein theshape profile is a three-dimensional shape profile assembled from dataobtained from the plurality of laser light sensors.
 16. The system ofclaim 2, wherein the reference temperature distribution defines aplurality of reference temperatures of a plurality of portions of theglass sheet at the plurality of time points during the bending of theglass sheet in the second chamber.
 17. The system of claim 16, wherein afirst reference temperature of a first portion of the glass sheet at afirst time point in the reference temperature distribution during thebending of the glass sheet in the second chamber is different than asecond reference temperature of the first portion of the glass sheet ata second time point in the reference temperature distribution during thebending of the glass sheet in the second chamber.
 18. A method ofshaping a glass sheet, comprising: preheating the glass sheet on abending iron to a predetermined preheating temperature; bending thepreheated glass sheet by selectively heating the glass sheet with adevice that produces a beam of electromagnetic waves to a temperature atwhich at least a portion of the glass sheet sags; scanning the glasssheet with at least one thermal sensor at a plurality of time pointsduring the bending of the glass sheet and obtaining a temperatureprofile of the glass sheet at the plurality of time points from dataobtained from the at least one thermal sensor; scanning the glass sheetwith at least one positional sensor at the plurality of time pointsduring the bending of the glass sheet to obtain positional data forportions of the glass sheet; producing a shape profile for the glasssheet from the obtained positional data; concurrently comparing theobtained shape profile to a reference shape profile and comparing theobtained temperature profile to a reference temperature distribution;and controlling the device that produces ultra-high frequency,high-power electromagnetic waves to selectively heat the glass sheet tomatch the shape profile of the glass sheet to the reference shapeprofile and to match the temperature profile with the referencetemperature distribution.
 19. The method of claim 18, wherein the deviceproducing ultra-high frequency, high-power electromagnetic waves is agyrotron configured to produce waves with a frequency of at least 20 GHzand power of at least 5 kW.
 20. The method of claim 18, wherein the atleast one thermal sensor comprises at least one of an infrared (IR)scanner, an IR imaging sensor, a charged-coupled device (CCD), an IRlaser-light sensor device, a thermal imaging device, or a thermalscanner, and wherein the at least one positional sensor comprises atleast one of a charge-coupled device (CCD) or a laser-light sensor. 21.The method of claim 18, wherein the reference temperature distributiondefines a plurality of temperatures of a plurality of portions of theglass sheet at the plurality of time points during the bending of theglass sheet, wherein a first temperature of the plurality of portions ofthe glass sheet at a first time in the reference temperaturedistribution during the bending of the glass sheet is different than asecond temperature of the plurality of portions of the glass sheet at asecond time in the reference temperature distribution during the bendingof the glass sheet.